Sketching instrument



Aug- 16. 1932- A. A. HAMPTON 1.872.578

SKETCHING INSTRUMENT Filed Sept. 26. 1927 Patented ug. 16, 1.932l

UNITED STATES ALBERT A. HAMPTON, F LOS ANGELES, CALIFORNIA,

Application :nea september 26,' i927. serial'nq. 221,889. y

This invention relates to sketching instruments and more particularly tomaking perspective pictures.

An object of the present invention is to construct an instrument thatwill form any desired angle to be traced. on suitable material.

Another object of the present invention is to provide an instrument thatwill measure required angles of circles so that the cord Y of the anglemight be measured.

Another object of the present invention is to provide a sketchinginstrument with means for making radial lines.

Another object of the present invention is to provide a sketchinginstrument with a protractor.

Another object of the present invention is to provide a sketchinginstrument with an irregular curve for making irregular lines.

Another object of the present invention is to incorporate in a sketchinginstrument a protractor having a straight edge extending outwardtherefrom and an irregular curve connected thereto.

With these and other objects in view the invention consists in thefeatures of construction, combinations and arrangements of partshereinafter set forth, illustrated in the accompanying drawing and moreparticularly l pointed out in the appended claims.

In the drawing:

Figure l is a plan view of the instrument constructed from thintransparent material, the instrument shown in full lines in one positionand in dotted linesin another position to illustrate the pivot jointsand one of the various positions that the instrument might be turned.

Figure '2 is a fragmentary view showing 40 how the various parts of theinstrument are pivotally connected together.

The protractor 3 extends through an arc of two hundred and seventydegrees but may extend through any portion thereof or a complete circleand has two integral bars 4 and 5 extending outward at right anglestherefrom.

Pivoted to the end of bar 5 is an irregular curve 6 commonly known as aFrench curve and is provided with a series of holes 7 for making circles"or portions thereof in addition to irregular curvedlines that may beformed by the outline thereof. n j

' The" bar 8 paralleling barf 5 and bar 9 paralleling the irregularcurve 6 are pivotally connectedA together, the bar "8 being pivotallyconnected to one end of the curve 6 while one end of the bar 9 ispivotally connected to the center of the protractor 3.

The bars 5, 8 and 9 Yare pivotally connected together by thimbles 10which are hollow so that a working point may be seen through any of thethimbles, this feature being most important in the application of theprotractor and curve.

The bars 4, 5, 8 and 9 are graduated so that the distance of lines maybe determined when making a drawing, while the edge l1 of bar 9 isalways in alignment with the center of the protractor so that a seriesof radial lines may be drawn from a given point.

It will be noted in the dotted position in Figure l or in fact wheneverbar 9 is drawn to the left of bar 4 that three sides of any rectanglecan be measured and drawn by the edges of bars 8, 4 and 7, and all thatis necessary to complete the rectangle is to lay an ordinary straightedge or angle across the remaining side and trace the edge thereof.

It is obvious that the field for the various uses of this sketchinginstrument in making drawings is almost unlimited and that any angle orpair of lines may be drawn with the instrument in the relative positionto the an* gle or pair of lines.

The instrument is suitable for making perspective views, circles, radiallines, irregular curved lines, parallel lines, etc.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is n 1. The combination of an irregular curve,three bars, said bars and said curve being pivotally Connected togetherto form a parallelogram.

2. In a sketching instrument, the combination of a protractor having aprojecting bar, an irregular curve pivoted at one end to said bar, a barpivoted at one end to said protraotor, and a second bar, connecting theother end of said rst named bar with the other end of the curve, wherebythe four points of pivotal connection define a regular quadrilateral.

3. In a sketching instrument, the combination of a protractor havingindicia thereon, and a projecting bar therewith, an irregular curvepivoted at one end to said bar, a 10 second bar pivoted near one end tothe center of such protractor,iand having an extension adapted to playover the indicia for indicatv ing the angular relation of suchfrbar, andar third bar pivotally connecting the other end` 15 of said second barto theV other end o=s`aid irregular curve, whereby the fourpoints vofpivotal connection define a regular quadrilateral. i

lIn testimonywhereof, I have signed iny u name to this specification.

` ALBERT A. .HAMPTON

